1. Field of the Invention
The present invention relates to a sheet conveying apparatus, a printing apparatus, and a processing apparatus being provided in apparatuses handling sheets and including a sheet conveying unit that separates a plurality of kinds of sheets one by one by the same separation unit and conveys the separated sheet to the subsequent process.
2. Description of the Related Art
In printing apparatus, sheets are generally separated one by one by a separation slope from a sheet stacking unit in which the sheets are stacked. Then, while the sheet is grasped firmly by a sheet conveying roller, the sheet is guided to a conveyance guide, and is conveyed to a printing mechanism.
In printing apparatus that make use of a plurality of kinds of sheets, techniques have been known in which in order to perform separation in accordance with sheets from a sheet stacking unit in which the sheets are stacked, the rotation center is provided in the vicinity of the upstream side end portion in the conveyance direction of the sheets, and the angle of a separation slope is made variable in accordance with the kind of sheet (for example, see Japanese Patent Laid-Open No. 2005-254711).
However, the rotation center of the separation slope is provided in the vicinity of the upstream side end portion in the conveyance direction of sheets, and thus, when the angle of the separation slope is changed, a step is generated in the joint portion of the separation slope and the guide member of the sheet conveyance path on the downstream side from the separation slope. The problem is caused in which conveyance by a sheet conveying roller is not straightly performed, or the like, and thus image quality may be degraded.
When sheet conveying pressure by the sheet conveying roller becomes larger, overlapped conveying easily occurs. Such a force is generated when the sheet conveying roller abuts a sheet. In addition, when the opposing force applied to the sheet by the separation slope becomes smaller, overlapped conveying easily occurs. Such a force is generated when the sheet conveying roller abuts the sheet.
At any rate, when a problem is caused in sheet conveyance, there is a possibility that the quality of a printed image is degraded.